DANIELMUTLU Actually, even though I was thinking the same thing, Google Desktop seems more complete than spotlight. For example, I can't have spotlight search my Adium logs because there's no plugin available but they easily showed up in Google Desktop. Also, I like how there's a text preview of all your search results to better investigate them. The program also seems to try to be an app launcher as well and does a pretty good job as it seems to put applications at the top of search results for quick launching. The indexing does take up a lot of time and cpu but that's really all it is. I actually did uninstall the program but I think I'll try it for a while.
(Version 1.0.0.155)